include: drivers: misc: add rpi_pico pio driver in doc tree

Mount the Raspberry Pi Pico PIO driver into the Misc. drivers
doxygen group.

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

include/zephyr/drivers/misc/pio_rpi_pico/pio_rpi_pico.h

@@ -6,9 +6,23 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+/**
+ * @file
+ * @brief Header file for Raspberry Pi Pico PIO driver
+ * @ingroup pio_rpi_pico_interface
+ */
+
 #ifndef ZEPHYR_DRIVERS_MISC_PIO_PICO_RPI_PIO_PICO_RPI_H_
 #define ZEPHYR_DRIVERS_MISC_PIO_PICO_RPI_PIO_PICO_RPI_H_
 
+/**
+ * @brief Raspberry Pi Pico PIO driver APIs
+ * @defgroup pio_rpi_pico_interface Raspberry Pi Pico PIO Driver APIs
+ * @ingroup misc_interfaces
+ *
+ * @{
+ */
+
 #include <zephyr/devicetree/gpio.h>
 
 #include <hardware/pio.h>
@@ -146,4 +160,8 @@ PIO pio_rpi_pico_get_pio(const struct device *dev);
  */
 int pio_rpi_pico_allocate_sm(const struct device *dev, size_t *sm);
 
+/**
+ * @}
+ */
+
 #endif /* ZEPHYR_DRIVERS_MISC_PIO_PICO_RPI_PIO_PICO_RPI_H_ */